grub2: fix several CVEs

Backport CVE patches from upstream to fix: CVE-2021-3695 CVE-2021-3696 CVE-2021-3697 CVE-2022-28733 CVE-2022-28734 CVE-2022-28735 Backport the following 5 patches to make CVE patches be applied smoothly. video-Remove-trailing-whitespaces.patch video-readers-jpeg-Abort-sooner-if-a-read-operation-.patch video-readers-jpeg-Refuse-to-handle-multiple-start-o.patch Signed-off-by: Yongxin Liu <yongxin.liu@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
cracked-machine · Aug 21, 2022 · db43401 · db43401
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diff --git a/...s-bsp/grub/files/CVE-2021-3695-video-readers-png-Drop-greyscale-support-to-fix-heap.patch b/...s-bsp/grub/files/CVE-2021-3695-video-readers-png-Drop-greyscale-support-to-fix-heap.patch
@@ -0,0 +1,179 @@
+From e623866d9286410156e8b9d2c82d6253a1b22d08 Mon Sep 17 00:00:00 2001
+From: Daniel Axtens <dja@axtens.net>
+Date: Tue, 6 Jul 2021 18:51:35 +1000
+Subject: [PATCH] video/readers/png: Drop greyscale support to fix heap
+ out-of-bounds write
+
+A 16-bit greyscale PNG without alpha is processed in the following loop:
+
+      for (i = 0; i < (data->image_width * data->image_height);
+	   i++, d1 += 4, d2 += 2)
+	{
+	  d1[R3] = d2[1];
+	  d1[G3] = d2[1];
+	  d1[B3] = d2[1];
+	}
+
+The increment of d1 is wrong. d1 is incremented by 4 bytes per iteration,
+but there are only 3 bytes allocated for storage. This means that image
+data will overwrite somewhat-attacker-controlled parts of memory - 3 bytes
+out of every 4 following the end of the image.
+
+This has existed since greyscale support was added in 2013 in commit
+3ccf16dff98f (grub-core/video/readers/png.c: Support grayscale).
+
+Saving starfield.png as a 16-bit greyscale image without alpha in the gimp
+and attempting to load it causes grub-emu to crash - I don't think this code
+has ever worked.
+
+Delete all PNG greyscale support.
+
+Fixes: CVE-2021-3695
+
+Signed-off-by: Daniel Axtens <dja@axtens.net>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+
+Upstream-Status: Backport
+CVE: CVE-2021-3695
+
+Reference to upstream patch:
+https://git.savannah.gnu.org/cgit/grub.git/commit/?id=e623866d9286410156e8b9d2c82d6253a1b22d08
+
+Signed-off-by: Yongxin Liu <yongxin.liu@windriver.com>
+---
+ grub-core/video/readers/png.c | 87 +++--------------------------------
+ 1 file changed, 7 insertions(+), 80 deletions(-)
+
+diff --git a/grub-core/video/readers/png.c b/grub-core/video/readers/png.c
+index 35ae553c8..a3161e25b 100644
+--- a/grub-core/video/readers/png.c
++++ b/grub-core/video/readers/png.c
+@@ -100,7 +100,7 @@ struct grub_png_data
+
+   unsigned image_width, image_height;
+   int bpp, is_16bit;
+-  int raw_bytes, is_gray, is_alpha, is_palette;
++  int raw_bytes, is_alpha, is_palette;
+   int row_bytes, color_bits;
+   grub_uint8_t *image_data;
+
+@@ -296,13 +296,13 @@ grub_png_decode_image_header (struct grub_png_data *data)
+     data->bpp = 3;
+   else
+     {
+-      data->is_gray = 1;
+-      data->bpp = 1;
++      return grub_error (GRUB_ERR_BAD_FILE_TYPE,
++			 "png: color type not supported");
+     }
+
+   if ((color_bits != 8) && (color_bits != 16)
+       && (color_bits != 4
+-	  || !(data->is_gray || data->is_palette)))
++	  || !data->is_palette))
+     return grub_error (GRUB_ERR_BAD_FILE_TYPE,
+                        "png: bit depth must be 8 or 16");
+
+@@ -331,7 +331,7 @@ grub_png_decode_image_header (struct grub_png_data *data)
+     }
+
+ #ifndef GRUB_CPU_WORDS_BIGENDIAN
+-  if (data->is_16bit || data->is_gray || data->is_palette)
++  if (data->is_16bit || data->is_palette)
+ #endif
+     {
+       data->image_data = grub_calloc (data->image_height, data->row_bytes);
+@@ -899,27 +899,8 @@ grub_png_convert_image (struct grub_png_data *data)
+       int shift;
+       int mask = (1 << data->color_bits) - 1;
+       unsigned j;
+-      if (data->is_gray)
+-	{
+-	  /* Generic formula is
+-	     (0xff * i) / ((1U << data->color_bits) - 1)
+-	     but for allowed bit depth of 1, 2 and for it's
+-	     equivalent to
+-	     (0xff / ((1U << data->color_bits) - 1)) * i
+-	     Precompute the multipliers to avoid division.
+-	  */
+-
+-	  const grub_uint8_t multipliers[5] = { 0xff, 0xff, 0x55, 0x24, 0x11 };
+-	  for (i = 0; i < (1U << data->color_bits); i++)
+-	    {
+-	      grub_uint8_t col = multipliers[data->color_bits] * i;
+-	      palette[i][0] = col;
+-	      palette[i][1] = col;
+-	      palette[i][2] = col;
+-	    }
+-	}
+-      else
+-	grub_memcpy (palette, data->palette, 3 << data->color_bits);
++
++      grub_memcpy (palette, data->palette, 3 << data->color_bits);
+       d1c = d1;
+       d2c = d2;
+       for (j = 0; j < data->image_height; j++, d1c += data->image_width * 3,
+@@ -957,60 +938,6 @@ grub_png_convert_image (struct grub_png_data *data)
+       return;
+     }
+
+-  if (data->is_gray)
+-    {
+-      switch (data->bpp)
+-	{
+-	case 4:
+-	  /* 16-bit gray with alpha.  */
+-	  for (i = 0; i < (data->image_width * data->image_height);
+-	       i++, d1 += 4, d2 += 4)
+-	    {
+-	      d1[R4] = d2[3];
+-	      d1[G4] = d2[3];
+-	      d1[B4] = d2[3];
+-	      d1[A4] = d2[1];
+-	    }
+-	  break;
+-	case 2:
+-	  if (data->is_16bit)
+-	    /* 16-bit gray without alpha.  */
+-	    {
+-	      for (i = 0; i < (data->image_width * data->image_height);
+-		   i++, d1 += 4, d2 += 2)
+-		{
+-		  d1[R3] = d2[1];
+-		  d1[G3] = d2[1];
+-		  d1[B3] = d2[1];
+-		}
+-	    }
+-	  else
+-	    /* 8-bit gray with alpha.  */
+-	    {
+-	      for (i = 0; i < (data->image_width * data->image_height);
+-		   i++, d1 += 4, d2 += 2)
+-		{
+-		  d1[R4] = d2[1];
+-		  d1[G4] = d2[1];
+-		  d1[B4] = d2[1];
+-		  d1[A4] = d2[0];
+-		}
+-	    }
+-	  break;
+-	  /* 8-bit gray without alpha.  */
+-	case 1:
+-	  for (i = 0; i < (data->image_width * data->image_height);
+-	       i++, d1 += 3, d2++)
+-	    {
+-	      d1[R3] = d2[0];
+-	      d1[G3] = d2[0];
+-	      d1[B3] = d2[0];
+-	    }
+-	  break;
+-	}
+-      return;
+-    }
+-
+     {
+   /* Only copy the upper 8 bit.  */
+ #ifndef GRUB_CPU_WORDS_BIGENDIAN
+-- 
+2.34.1
+
diff --git a/...es-bsp/grub/files/CVE-2021-3696-video-readers-png-Avoid-heap-OOB-R-W-inserting-huff.patch b/...es-bsp/grub/files/CVE-2021-3696-video-readers-png-Avoid-heap-OOB-R-W-inserting-huff.patch
@@ -0,0 +1,50 @@
+From 210245129c932dc9e1c2748d9d35524fb95b5042 Mon Sep 17 00:00:00 2001
+From: Daniel Axtens <dja@axtens.net>
+Date: Tue, 6 Jul 2021 23:25:07 +1000
+Subject: [PATCH] video/readers/png: Avoid heap OOB R/W inserting huff table
+ items
+
+In fuzzing we observed crashes where a code would attempt to be inserted
+into a huffman table before the start, leading to a set of heap OOB reads
+and writes as table entries with negative indices were shifted around and
+the new code written in.
+
+Catch the case where we would underflow the array and bail.
+
+Fixes: CVE-2021-3696
+
+Signed-off-by: Daniel Axtens <dja@axtens.net>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+
+Upstream-Status: Backport
+CVE: CVE-2021-3696
+
+Reference to upstream patch:
+https://git.savannah.gnu.org/cgit/grub.git/commit/?id=210245129c932dc9e1c2748d9d35524fb95b5042
+
+Signed-off-by: Yongxin Liu <yongxin.liu@windriver.com>
+---
+ grub-core/video/readers/png.c | 7 +++++++
+ 1 file changed, 7 insertions(+)
+
+diff --git a/grub-core/video/readers/png.c b/grub-core/video/readers/png.c
+index a3161e25b..d7ed5aa6c 100644
+--- a/grub-core/video/readers/png.c
++++ b/grub-core/video/readers/png.c
+@@ -438,6 +438,13 @@ grub_png_insert_huff_item (struct huff_table *ht, int code, int len)
+   for (i = len; i < ht->max_length; i++)
+     n += ht->maxval[i];
+
++  if (n > ht->num_values)
++    {
++      grub_error (GRUB_ERR_BAD_FILE_TYPE,
++		  "png: out of range inserting huffman table item");
++      return;
++    }
++
+   for (i = 0; i < n; i++)
+     ht->values[ht->num_values - i] = ht->values[ht->num_values - i - 1];
+
+-- 
+2.34.1
+
diff --git a/...es-bsp/grub/files/CVE-2021-3697-video-readers-jpeg-Block-int-underflow-wild-pointer.patch b/...es-bsp/grub/files/CVE-2021-3697-video-readers-jpeg-Block-int-underflow-wild-pointer.patch
@@ -0,0 +1,84 @@
+From 22a3f97d39f6a10b08ad7fd1cc47c4dcd10413f6 Mon Sep 17 00:00:00 2001
+From: Daniel Axtens <dja@axtens.net>
+Date: Wed, 7 Jul 2021 15:38:19 +1000
+Subject: [PATCH] video/readers/jpeg: Block int underflow -> wild pointer write
+
+Certain 1 px wide images caused a wild pointer write in
+grub_jpeg_ycrcb_to_rgb(). This was caused because in grub_jpeg_decode_data(),
+we have the following loop:
+
+for (; data->r1 < nr1 && (!data->dri || rst);
+     data->r1++, data->bitmap_ptr += (vb * data->image_width - hb * nc1) * 3)
+
+We did not check if vb * width >= hb * nc1.
+
+On a 64-bit platform, if that turns out to be negative, it will underflow,
+be interpreted as unsigned 64-bit, then be added to the 64-bit pointer, so
+we see data->bitmap_ptr jump, e.g.:
+
+0x6180_0000_0480 to
+0x6181_0000_0498
+     ^
+     ~--- carry has occurred and this pointer is now far away from
+          any object.
+
+On a 32-bit platform, it will decrement the pointer, creating a pointer
+that won't crash but will overwrite random data.
+
+Catch the underflow and error out.
+
+Fixes: CVE-2021-3697
+
+Signed-off-by: Daniel Axtens <dja@axtens.net>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+
+Upstream-Status: Backport
+CVE: CVE-2021-3697
+
+Reference to upstream patch:
+https://git.savannah.gnu.org/cgit/grub.git/commit/?id=22a3f97d39f6a10b08ad7fd1cc47c4dcd10413f6
+
+Signed-off-by: Yongxin Liu <yongxin.liu@windriver.com>
+---
+ grub-core/video/readers/jpeg.c | 10 +++++++++-
+ 1 file changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/grub-core/video/readers/jpeg.c b/grub-core/video/readers/jpeg.c
+index 579bbe8a4..09596fbf5 100644
+--- a/grub-core/video/readers/jpeg.c
++++ b/grub-core/video/readers/jpeg.c
+@@ -23,6 +23,7 @@
+ #include <grub/mm.h>
+ #include <grub/misc.h>
+ #include <grub/bufio.h>
++#include <grub/safemath.h>
+
+ GRUB_MOD_LICENSE ("GPLv3+");
+
+@@ -699,6 +700,7 @@ static grub_err_t
+ grub_jpeg_decode_data (struct grub_jpeg_data *data)
+ {
+   unsigned c1, vb, hb, nr1, nc1;
++  unsigned stride_a, stride_b, stride;
+   int rst = data->dri;
+   grub_err_t err = GRUB_ERR_NONE;
+
+@@ -711,8 +713,14 @@ grub_jpeg_decode_data (struct grub_jpeg_data *data)
+     return grub_error (GRUB_ERR_BAD_FILE_TYPE,
+ 		       "jpeg: attempted to decode data before start of stream");
+
++  if (grub_mul(vb, data->image_width, &stride_a) ||
++      grub_mul(hb, nc1, &stride_b) ||
++      grub_sub(stride_a, stride_b, &stride))
++    return grub_error (GRUB_ERR_BAD_FILE_TYPE,
++		       "jpeg: cannot decode image with these dimensions");
++
+   for (; data->r1 < nr1 && (!data->dri || rst);
+-       data->r1++, data->bitmap_ptr += (vb * data->image_width - hb * nc1) * 3)
++       data->r1++, data->bitmap_ptr += stride * 3)
+     for (c1 = 0;  c1 < nc1 && (!data->dri || rst);
+ 	c1++, rst--, data->bitmap_ptr += hb * 3)
+       {
+-- 
+2.34.1
+
diff --git a/meta/recipes-bsp/grub/files/CVE-2022-28733-net-ip-Do-IP-fragment-maths-safely.patch b/meta/recipes-bsp/grub/files/CVE-2022-28733-net-ip-Do-IP-fragment-maths-safely.patch
@@ -0,0 +1,63 @@
+From 3e4817538de828319ba6d59ced2fbb9b5ca13287 Mon Sep 17 00:00:00 2001
+From: Daniel Axtens <dja@axtens.net>
+Date: Mon, 20 Dec 2021 19:41:21 +1100
+Subject: [PATCH] net/ip: Do IP fragment maths safely
+
+We can receive packets with invalid IP fragmentation information. This
+can lead to rsm->total_len underflowing and becoming very large.
+
+Then, in grub_netbuff_alloc(), we add to this very large number, which can
+cause it to overflow and wrap back around to a small positive number.
+The allocation then succeeds, but the resulting buffer is too small and
+subsequent operations can write past the end of the buffer.
+
+Catch the underflow here.
+
+Fixes: CVE-2022-28733
+
+Signed-off-by: Daniel Axtens <dja@axtens.net>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+
+Upstream-Status: Backport
+CVE: CVE-2022-28733
+
+Reference to upstream patch:
+https://git.savannah.gnu.org/cgit/grub.git/commit/?id=3e4817538de828319ba6d59ced2fbb9b5ca13287
+
+Signed-off-by: Yongxin Liu <yongxin.liu@windriver.com>
+
+---
+ grub-core/net/ip.c | 10 +++++++++-
+ 1 file changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/grub-core/net/ip.c b/grub-core/net/ip.c
+index e3d62e97f..3c3d0be0e 100644
+--- a/grub-core/net/ip.c
++++ b/grub-core/net/ip.c
+@@ -25,6 +25,7 @@
+ #include <grub/net/netbuff.h>
+ #include <grub/mm.h>
+ #include <grub/priority_queue.h>
++#include <grub/safemath.h>
+ #include <grub/time.h>
+
+ struct iphdr {
+@@ -512,7 +513,14 @@ grub_net_recv_ip4_packets (struct grub_net_buff *nb,
+     {
+       rsm->total_len = (8 * (grub_be_to_cpu16 (iph->frags) & OFFSET_MASK)
+ 			+ (nb->tail - nb->data));
+-      rsm->total_len -= ((iph->verhdrlen & 0xf) * sizeof (grub_uint32_t));
++
++      if (grub_sub (rsm->total_len, (iph->verhdrlen & 0xf) * sizeof (grub_uint32_t),
++		    &rsm->total_len))
++	{
++	  grub_dprintf ("net", "IP reassembly size underflow\n");
++	  return GRUB_ERR_NONE;
++	}
++
+       rsm->asm_netbuff = grub_netbuff_alloc (rsm->total_len);
+       if (!rsm->asm_netbuff)
+ 	{
+-- 
+2.34.1
+